Can Blood Flow Restriction Be the Key to Reducing Quadriceps Weakness in the Early and Mid-Phases After Anterior Cruciate Ligament Reconstruction with a Hamstring Graft? A Systematic Review of Randomized Controlled Trials

Abstract

Background: Injury to the anterior cruciate ligament is one of the most common knee injuries. Following anterior cruciate ligament reconstruction, strength deficits and reduced quadriceps and hamstring muscle mass are common. Traditional strengthening protocols recommend the use of heavy loads. However, following surgery, heavy-load exercises are contraindicated to protect the joint and graft. Blood flow restriction resistance training is an alternative that optimizes muscle recovery. The aim of this study was to evaluate the effects of blood flow restriction resistance training on muscle mass and strength after ACLR. Methods: The Pubmed, Cochrane Library, and PEDro databases were used to constitute the corpus of this systematic review. The methodological quality of the studies was assessed with the Cochrane Collaboration’s analysis grid. Results: Thirty-four articles were identified in the initial search, and five randomized controlled trials were included in this review. Not all studies reported significant results regarding strength and muscle mass. Two of these studies observed a significant improvement in strength associated with blood flow restriction resistance training compared with the control group. A significant increase in muscle mass was observed in one study. Conclusions: The blood flow restriction resistance training method shows superior efficacy to training without occlusion, yet this device has not been shown to be more effective than heavy-load resistance training in terms of muscular strength and muscle mass. Blood flow restriction resistance training shows superior efficacy in both these variables when used with low loads. However, there are still few random controlled trials on this subject, and this review presents their limitations and biases. Future research is needed on guidelines for the application of blood flow restriction resistance training in clinical populations.

Full text

Academic Editors: Jacobo Á. Rubio
Arias and Luis Manuel Martínez
Aranda
Received: 19 December 2024
Revised: 27 January 2025
Accepted: 28 January 2025
Published: 6 February 2025
Citation: Moiroux--Sahraoui, A.;
Mazeas, J.; Blossier, M.; Douryang, M.;
Kakavas, G.; Hewett, T.E.; Forelli, F.
Can Blood Flow Restriction Be the
Key to Reducing Quadriceps
Weakness in the Early and
Mid-Phases After Anterior Cruciate
Ligament Reconstruction with a
Hamstring Graft? A Systematic
Review of Randomized Controlled
Trials. Diagnostics 2025,15, 382.
https://doi.org/10.3390/
diagnostics15030382
Copyright: © 2025 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license
(https://creativecommons.org/
licenses/by/4.0/).
Systematic Review
Can Blood Flow Restriction Be the Key to Reducing Quadriceps
Weakness in the Early and Mid-Phases After Anterior Cruciate
Ligament Reconstruction with a Hamstring Graft? A Systematic
Review of Randomized Controlled Trials
Ayrton Moiroux--Sahraoui
1, 2,
* , Jean Mazeas
1,2
, Marine Blossier
2
, Maurice Douryang
3
, Georges Kakavas
4,5
,
Timothy E. Hewett 6and Florian Forelli 2,7,8,*
1Orthosport Rehab Center, 95330 Domont, France; jeanmazeas@gmail.com
2Orthopaedic Surgery Department, Clinic of Domont, Ramsay Healthcare, @OrthoLab,
95460 Domont, France; orthosport.kine@gmail.com
3Department of Physiotherapy and Physical Medicine, University of Dschang,
Dschang P.O. Box 96, Cameroon; douryangmaurice@gmail.com
4Fysiotek Spine & Sports Lab, 11635 Athens, Greece; georgios.kakavas@gmail.com
5Department of Physical Education and Sport Sciences, ErgoMech-Lab, University of Thessaly,
421 00 Volos, Greece
6Department of Orthopaedic Surgery, Marshall University, Huntington, WV 25705, USA;
hewettt@marshall.edu
7Haute-Ecole Arc Santé, HES-SO University of Applied Sciences and Arts Western Switzerland,
2000 Neuchâtel, Switzerland
8Société Française des Masseurs—Kinésithérapeutes du Sport Lab, 93380 Pierrefite sur Seine, France
*Correspondence: ayrton.moirouxsahraoui@gmail.com (A.M.--S.); florian.forelli@ramsaysante.fr (F.F.);
Tel.:+33-769495275 (F.F.)
Abstract: Background: Injury to the anterior cruciate ligament is one of the most common
knee injuries. Following anterior cruciate ligament reconstruction, strength deficits and
reduced quadriceps and hamstring muscle mass are common. Traditional strengthening
protocols recommend the use of heavy loads. However, following surgery, heavy-load
exercises are contraindicated to protect the joint and graft. Blood flow restriction resistance
training is an alternative that optimizes muscle recovery. The aim of this study was to
evaluate the effects of blood flow restriction resistance training on muscle mass and strength
after ACLR. Methods: The Pubmed, Cochrane Library, and PEDro databases were used to
constitute the corpus of this systematic review. The methodological quality of the studies
was assessed with the Cochrane Collaboration’s analysis grid. Results: Thirty-four articles
were identified in the initial search, and five randomized controlled trials were included
in this review. Not all studies reported significant results regarding strength and muscle
mass. Two of these studies observed a significant improvement in strength associated with
blood flow restriction resistance training compared with the control group. A significant
increase in muscle mass was observed in one study. Conclusions: The blood flow restriction
resistance training method shows superior efficacy to training without occlusion, yet this
device has not been shown to be more effective than heavy-load resistance training in terms
of muscular strength and muscle mass. Blood flow restriction resistance training shows
superior efficacy in both these variables when used with low loads. However, there are still
few random controlled trials on this subject, and this review presents their limitations and
biases. Future research is needed on guidelines for the application of blood flow restriction
resistance training in clinical populations.
Diagnostics 2025,15, 382 https://doi.org/10.3390/diagnostics15030382

Diagnostics 2025,15, 382 2 of 13
Keywords: blood flow restriction; anterior cruciate ligament reconstruction; strength;
hypertrophy
1. Introduction
Anterior cruciate ligament (ACL) injury is one of the most common and serious
knee injuries [
1
], with over 50,000 surgeries performed in France in 2019 [
2
], and around
400,000 cases annually in the U.S [
3
]. The risk is higher for female athletes, who are four
to seven times more likely to suffer an ACL injury than male athletes at the same level [
4
].
Treatment depends on factors like functional instability, the type of injury, and the patient’s
activity level, with surgery often recommended for young athletes [
5
]. Rehabilitation is key
post-surgery, following a protocol that is regularly updated, most recently in 2023 [6].
A key focus is the importance of quadriceps weakness after ACLR. This weakness is
often caused by neurophysiological mechanisms, particularly arthrogenic muscle inhibition,
which limits the muscle’s ability to recover, even after ACLR [
7
,
8
]. This condition compli-
cates recovery and the return to optimal functional levels [
9
]. To address this challenge,
various rehabilitation approaches have been developed to stimulate muscle recovery and
strength. These include electromyostimulation (EMS), which activates muscles through
electrical impulses; vibration training, which leverages mechanical oscillations to enhance
muscle contractions; aquatic therapy, which offers a low-impact environment for resistance
training; and isokinetic training, which provides controlled resistance throughout a range
of motion to target muscle strength. While these methods have demonstrated effectiveness
in certain contexts, limitations such as access, patient adherence, or applicability during
early rehabilitation phases may reduce their overall utility [
6
]. Blood flow restriction (BFR)
emerges as a promising alternative to address this weakness. BFR devices are increasingly
utilized in rehabilitation and strength training to promote muscle growth and recovery
while using lower loads. Their handling requires precision to ensure safety and effective-
ness. For instance, selecting the appropriate cuff size is crucial, as too narrow or wide a
cuff can affect the pressure distribution. The applied pressure should be individualized
based on limb circumference and arterial occlusion pressure (AOP), often determined with
a Doppler ultrasound or an automated system. Devices like pneumatic cuffs or elastic
bands should be positioned at the proximal part of the limb, ensuring proper placement
and secure fastening without excessive constriction. Monitoring is essential during sessions
to check for signs of discomfort, numbness, or vascular complications. Finally, practitioners
should follow evidence-based guidelines, adjusting pressures, rest periods, and training
loads according to the individual’s goals and tolerance. Proper education and adherence to
protocols are vital for maximizing BFR’s benefits while minimizing risks.
BFR, when used in combination with low-load resistance training (BFR-RT), involves
application of an external compression device (such as pneumatic cuff) to a limb to restrict
blood flow to the muscle, creating a hypoxic environment that induces high metabolic
stress. This environment promotes muscular adaptations at low loads, effectively enabling
strength and muscle growth similar to that provided by high-load training, but without
the same joint stress. Meta-analyses, such as those by Hughes et al. and Patterson et al.,
report that BFR-RT can yield strength gains and hypertrophy comparable to that provided
by high-load resistance training, with intensities as low as 20–30% of the one-repetition
maximum (1RM) [
10
–
12
]. This approach is advantageous for ACLR patients in the early
stages of recovery, as traditional high-load exercises can place undue stress on the healing
graft (Figure 1).

Diagnostics 2025,15, 382 3 of 13
Centner et al. reported that BFR-RT specifically enhanced quadriceps strength post-
ACLR, and addressed the persistent muscle inhibition that often limits full recovery [
13
].
The study emphasized BFR’s role in the stimulation of protein synthesis and satellite cell
activation through metabolic stress rather than mechanical load, making it a particularly
valuable method for protection of the graft during early- and mid-phase rehabilitation [
14
].
Although further studies are needed to standardize BFR protocols and confirm long-term
outcomes, current evidence supports BFR’s potential for the reduction of post-ACLR
quadriceps deficits and the acceleration of functional recovery.
Diagnostics 2025, 15, x FOR PEER REVIEW 3 of 13
The study emphasized BFR’s role in the stimulation of protein synthesis and satellite cell
activation through metabolic stress rather than mechanical load, making it a particularly
valuable method for protection of the graft during early- and mid-phase rehabilitation
[14]. Although further studies are needed to standardize BFR protocols and conrm long-
term outcomes, current evidence supports BFR’s potential for the reduction of post-ACLR
quadriceps decits and the acceleration of functional recovery.
Figure 1. Comparison of dierent blood ow restriction (BFR) training devices and their applica-
tion on the thigh [15]. 1. Elastic BFR (Straps or Bands), 2. Automated Pneumatic BFR, 3. Manual
BFR (Pump and Gauge), 4. Personalized Pressure BFR (Integrated Gauge).
ACL injuries are common, and can have serious functional consequences that may
restrict participation in sports. After a reconstruction, rehabilitation aims to regain muscle
strength, particularly in the quadriceps and hamstring, which are most aected. Although
heavy loads are eective in strengthening muscles, they are contraindicated post-opera-
tively. BFR-RT, using low loads, is a promising alternative for promoting muscle recovery
while protecting the graft. The main objective of this review was to nd out whether re-
habilitation using BFR-RT results in a gain in strength and muscle mass compared to tra-
ditional rehabilitation after ACLR during the early and mid-phases.
2. Materials and Methods
This review followed the Preferred Reporting Items for Systematic reviews and
Meta-Analyses (PRISMA) 2020 statement for systematic reviews [16]. The review was not
registered a priori, and no patients or members of the public were involved.
Figure 1. Comparison of different blood flow restriction (BFR) training devices and their application
on the thigh [
15
]. 1. Elastic BFR (Straps or Bands), 2. Automated Pneumatic BFR, 3. Manual BFR
(Pump and Gauge), 4. Personalized Pressure BFR (Integrated Gauge).
ACL injuries are common, and can have serious functional consequences that may
restrict participation in sports. After a reconstruction, rehabilitation aims to regain muscle
strength, particularly in the quadriceps and hamstring, which are most affected. Al-
though heavy loads are effective in strengthening muscles, they are contraindicated post-
operatively. BFR-RT, using low loads, is a promising alternative for promoting muscle
recovery while protecting the graft. The main objective of this review was to find out
whether rehabilitation using BFR-RT results in a gain in strength and muscle mass com-
pared to traditional rehabilitation after ACLR during the early and mid-phases.

Diagnostics 2025,15, 382 4 of 13
2. Materials and Methods
This review followed the Preferred Reporting Items for Systematic reviews and Meta-
Analyses (PRISMA) 2020 statement for systematic reviews [
16
]. The review was not
registered a priori, and no patients or members of the public were involved.
2.1. Eligibility Criteria
Eligibility criteria for the inclusion of articles in this literature review were defined.
Inclusion criteria included a study population between 15 and 50 years old after ACLR with
a hamstring graft, the intervention (rehabilitation + BFR-RT), comparison to conventional
rehabilitation, assessment criteria (strength and/or muscle mass), and English language.
Conversely, some criteria led to the exclusion of articles, such as systematic reviews, meta-
analyses, and studies that involved participants with additional knee pathologies alongside
ACLR (other concomitant ligament reconstructions).
2.2. Information Sources, Literature Search, and Selection of Sources of Evidence
An exploratory search was performed in the MEDLINE database using the following
terms: ‘anterior cruciate ligament’ AND ‘reconstruction’ AND ‘blood flow restriction’. By
this preliminary search, MeSH terms, text word terms, and relevant keywords, as well as
search strategies from relevant systematic reviews, were identified, and in consultation
with the authors team, the final keyword string to be used for the search was developed
(Table 1).
Table 1. Search terms.
Construct Keywords
Population
Anterior cruciate ligament reconstruction, Anterior
cruciate ligament reconstruction graft, Anterior cruciate
ligament reconstruction surgery
Concept Blood flow restriction, Blood flow restriction therapy,
Blood Flow Restriction Training
Context Muscular strengthening, Resistance training, Strength
training, Strengthening program
Relevant studies were identified by the lead author by a systematic search of four
online databases from January 2018 to December 2023 (MEDLINE via PubMed, Cochrane
Library, and PEDro). The reference lists of the included studies and key randomized
controlled trials were screened, and citation tracking was performed with Google Scholar,
in order to identify any potentially relevant studies that may have been missed in the
database search.
All articles were downloaded and transferred to the Zotero v.6.0.13 management
platform. They were cross-referenced and any duplicates were deleted before the selection
criteria were applied. Two reviewers (AMS and MB) independently screened all articles
for eligibility by title and abstract (Figure 2). The same independent reviewers performed
full-text screening to determine the final study selection. Any discrepancies were resolved
during a consensus meeting first between reviewers, and if required with the participation
of the senior author.

Diagnostics 2025,15, 382 5 of 13
Diagnostics 2025, 15, x FOR PEER REVIEW 5 of 13
Figure 2. Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Sys-
tematic Reviews ow chart.
2.3. Data Extraction and Quality Assessment
The data extracted by AMS and MB included the names of authors, year of publica-
tion, name of article, publication journal, nationality of study, strengthening protocol
used, study type, number of participants, participant characteristics, interventions used,
and study results. When analyzing the articles, various data from the included studies
were used. A ow chart according to the PRISMA 2020 statement was employed [16]. All
articles were downloaded and transferred to the Zotero v6.0.13 management platform.
They were cross-referenced and any duplicates were deleted before the selection criteria
were applied. Two reviewers (AMS and MB) independently screened all the articles for
eligibility by title and abstract (Figure2). The same independent reviewers performed full-
Records screened
(n = 34)
Records excluded
(n = 21)
Reports sought for retrieval
(n =7)
Reports not retrieved
(n =0)
Reports assessed for eligibility
(n = 1)
Reports excluded:
Full text not available (n = 1)
Preoperative protocol (n = 1)
Studies included in review
(n = 5)
Screening
Included
Records identified from:
Databases (n = 62)
Records removed before screen-
ing:
Duplicate records removed
(n = 28)
Identification of studies via databases and registers
Identification
Figure 2. Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for
Systematic Reviews flow chart.
2.3. Data Extraction and Quality Assessment
The data extracted by AMS and MB included the names of authors, year of publication,
name of article, publication journal, nationality of study, strengthening protocol used, study
type, number of participants, participant characteristics, interventions used, and study
results. When analyzing the articles, various data from the included studies were used.
A flow chart according to the PRISMA 2020 statement was employed [
16
]. All articles
were downloaded and transferred to the Zotero v6.0.13 management platform. They were
cross-referenced and any duplicates were deleted before the selection criteria were applied.
Two reviewers (AMS and MB) independently screened all the articles for eligibility by title

Diagnostics 2025,15, 382 6 of 13
and abstract (Figure 2). The same independent reviewers performed full-text screening to
determine the final study selection. Any discrepancies were resolved during a consensus
meeting, first between reviewers, and then, if required, with the participation of the senior
author (Figure 2).
The validity of the identified articles was assessed with the Cochrane Risk of Bias
Scale. The Cochrane Collaboration Risk of Bias Scale assesses the risk of bias in randomized
clinical trials. This tool was updated in 2011. It was determined whether each article
presented a risk. For each bias, it was determined whether the risk of bias was low, high,
or indeterminate.
3. Results
After the deletion of duplicates, thirty-four articles were read. Twenty-one (62%) of
them did not meet the inclusion criteria. Therefore, five were selected for inclusion in the
analysis (Table 2). These five randomized controlled trials were included in this systematic
review. These five randomized controlled trials directly examined the use of BFR-RT in
patients who have undergone ACLR (Table 3).
Table 2. General characteristics of included studies.
References Study Title Aim of the Study Country of Study N (Participants)
Erickson et al. [17]
(2019)
Effect of Blood Flow
Restriction Training on
Quadriceps Muscle
Strength, Morphology,
Physiology and Knee
Biomechanics Before and
After Anterior Cruciate
Ligament Reconstruction
Evaluate the effect of
BFR-RT on quadriceps
strength and knee
biomechanics, and
identify the potential
mechanism(s) of action of
BFR-RT at the cellular and
morphological levels of
the quadriceps.
USA (University of
Kentucky)
A total of 60 patients (male or female,
15–40 years) with an isolated ACL tear
or with a meniscus tear, without a
specified graft type.
They were randomly assigned to the
following groups:
- Physiotherapy + BFR (n = 30)
(BFR-RT group)
- Physiotherapy + BFR placebo
(n = 30) (standard of care group)
Hughes et al. [18]
(2019)
Comparing the
Effectiveness of Blood
Flow Restriction and
Traditional Heavy Load
Resistance Training in the
Post-Surgery
Rehabilitation of Anterior
Cruciate Ligament
Reconstruction
Compare the efficacy of
BFR-RT and traditional
heavy-load training
(HL-RT) in improving
skeletal muscle
hypertrophy and strength,
physical function, pain,
and effusion in patients
undergoing anterior
cruciate ligament
reconstruction.
UK (National
Health Service)
A total of 28 patients (11 women and
17 men, age: 29 ±7 years) underwent
unilateral autograft surgery with a
graft from the hamstrings. They were
randomly assigned to the following
groups:
- HL-RT (n = 14)
- BFR-RT (n = 14)
Curran et al. [19]
(2019)
Blood Flow Restriction
Training Applied with
High-Intensity Exercise
does not improve
Quadriceps Muscle
Function After Anterior
Cruciate Ligament
Reconstruction
Examine the efficacy of
BFR-RT with
high-intensity exercise on
the recovery of quadriceps
muscle function in
patients after anterior
cruciate ligament
reconstruction.
USA (University of
Michigan)
A total of 34 patients (19 women,
15 men, age: 16.5
±
2.7 years) who had
undergone ACLR were randomly
assigned to one of four groups:
- Concentric (n = 8)
- Eccentric (n = 8)
- Concentric + BFR-RT (n = 9)
- Eccentric + BFR-RT (n = 9)
Kacin et al. [20]
(2021)
Functional and molecular
adaptations of quadriceps
and hamstring muscles to
blood flow restricted
training in patients with
ACL rupture
Determine whether
LL-BFR-RT can increase
motor function and the
size of quadriceps and
hamstring muscles in
patients after ACL
reconstruction.
Slovenia (Ljubljana)
A total of 18 participants (9 women
and 9 men, age: 37.5 ±9 years)
underwent ACLR. A total of 12 people
were divided into three groups:
- LL-BFR-RT(n = 6)
- Control group (n = 6)
- No-intervention control group
(n = 6), used for muscle biopsy
analysis.

Diagnostics 2025,15, 382 7 of 13
Table 2. Cont.
References Study Title Aim of the Study Country of Study N (Participants)
De Melo et al. [21]
(2022)
Comparison of
Quadriceps and
Hamstring Muscle
Strength After Exercises
with and without Blood
Flow Restriction
Following Anterior
Cruciate Ligament
Surgery
Compare quadriceps and
hamstring muscle strength
gain in patients after ACL
reconstruction surgery
using exercises with and
without BFR-RT.
Brazil (University of
São Paulo)
A total of 28 participants (male and
female, age: 18–59) underwent ACLR
using a hamstring autograft.The were
randomly assigned to the following
groups:
- BFR-RT group (n = 14)
- Control group (n = 14)
Note: ACL, anterior cruciate ligament; BFR, blood flow restriction.
Table 3. Overview of BFR-RT intervention protocols and main findings in ACLR studies.
References Duration nterventions Main Findings
Erickson et al. [17]
- Pre-surgical: 3X/week for
4 weeks
- BFR-RT post-surgery: Start
1 month before surgery and
resume at 2 weeks post-op.
3X/week for 4–5 months.
Sessions last 20 min.
- Standard post-surgery:
3X/week for 6–7 months,
divided into three stages
(3 days–2/6 weeks,
4–6 weeks, 3–5 months).
Home-based program
provided.
BFR-RT: Stopped 4 months post-surgery
for isolated ACL, or 5 months if meniscus
repair is included. Pressure defined by
manufacturer.
Placebo: Minimal pressure (<20 mm Hg).
All participants focused on quadriceps
strengthening.
- Quadriceps strength: Difference of 39 ±47 Nm
between groups.
- Muscle cross-sectional area: Difference of
27 ±32 cm2between groups.
Hughes et al. [18]8 weeks
2X/week (16 sessions), beginning on
day 14 post-op
BFR-RT group:
-
Warm-up: 5 min cycling, 10 reps
unilateral press with light load.
-
Unilateral press at 30% of 1RM
with 80% of LOP, four sets (30, 15,
15, 15 reps) with 30 s rest and con-
tinuous BFR.
HL-RT group: Same warm-up and
unilateral press at 70% of 1RM, three sets
of 10 reps with 30 s rest.
Both groups followed a standard rehab
program 3X/week at home.
-
10RM strength: Significant increase in both groups
(BFR-RT: 104 ±18%; HL-RT: 106 ±21%, p< 0.01),
with no difference between groups (p= 0.22).
- Kinetic force: Torque decrease in both; BFR-RT
group—significant increase at 150◦/s and 300◦/s.
- Muscle mass: Significant increase (BFR-RT:
5.8 ±0.2%, HL-RT: 6.7 ±0.3%, p< 0.01), with no
difference between groups (p= 0.33).
Curran et al. [19]8 weeks
2X/week (16 sessions), starting
10 weeks post-op
All participants followed standard
rehabilitation. 1RM assessed on first day,
then weekly.
Experimental (BFR-RT): five sets of
10 reps at 70% of 1RM unilateral leg press
with 2 min rest between sets; cuff deflated
during rest and reinflated for sets.
Pressure: 80% of LOP (110–186 mmHg).
Control: Same exercises and intensity
without occlusion.
- Kinetic force: BFR-RT = −12.4 ±19.2 Nm vs.
Control = −15.0 ±19.2 Nm, p= 0.49.
- Isometric strength: BFR-RT = −16.3 ±31.1 Nm vs.
Control = −11.8 ±38.3 Nm, p= 0.88.
- 1RM: BFR-RT = 2.44 ±1.21 kg vs.
Control = 2.10 ±0.95 kg, p= 0.24.
- No statistical difference (p< 0.05) for isokinetic,
isometric extension, and rectus femoris muscle
mass.
Kacin et al. [20]3 weeks
3X/week for nine sessions
BFR-RT group: four sets of knee
extension and flexion at 40RM until
failure with operated leg only, workload
constant. Cuff pressure: 150 mmHg.
Isotonic knee extension with 45 s rest
between first and third sets without
reperfusion; 90 s reperfusion after second
set. Same protocol for knee flexion.
Placebo: Same protocol with cuff inflated
to 20 mmHg.
- Knee extensors: Higher max torque at 60◦/s
(14 ±13% vs. −1±7%), total work at 60◦/s
(14 ±11% vs. 0 ±6%), max torque at 120◦/s
(10 ±9% vs. −4±7%), total work at 120◦/s
(8 ±5% vs. −2±5%) in BFR-RT group.
- Knee flexors: Max torque similar in both groups.
- Muscle cross-sectional area: Significantly higher
for quadriceps in BFR-RT group (5.0 ±3.4%) than
placebo (1.1 ±2.1%); hamstring similar between
groups.
De Melo et al. [21]12 weeks
2X/week
BFR-RT group: four sets (1×30, 3X15),
with 30 s rest between sets, at 30% MR.
Pressure: 80% of LOP.
Control group: three sets of 10 reps at
70% of 1RM. Pressure maintained during
all reps.
1RM tests conducted on leg press and
flexion machine for BFR training on
injured then uninjured leg.
- Knee extensor strength: Increase throughout cycle
for both; greater gain in BFR-RT from second
post-op period, with significant difference after
12 weeks. No difference in uninjured legs.
-
Knee flexor strength: Increase throughout cycle for
both, greater gain in BFR-RT from third post-op
period. No difference in uninjured legs.

Diagnostics 2025,15, 382 8 of 13
Among the included studies, five compared blood flow restriction resistance training
(BFR-RT) with control groups or other muscle strengthening methods (Table 1). BFR-RT
protocols varied in duration, intensity, and frequency, with programs lasting from three to
twelve weeks, and including between two and three sessions per week.
Most of these studies used muscle strength criteria to assess the effects of BFR-RT
on the quadriceps. Erickson et al. measured quadriceps strength, reporting a difference
of
39 ±47 Nm
between the BFR-RT and placebo groups [
17
]. Hughes et al. observed
comparable increases in 10RM strength between the BFR-RT and HL-RT groups (104
±
18%
vs.
106 ±21%
,p= 0.22), although a significant increase in isokinetic strength was noted in
the BFR-RT group at speeds of 150◦/s and 300◦/s (p< 0.001) [18].
Regarding muscle mass criteria, three studies measured the quadriceps cross-sectional
area or muscle thickness. Erickson et al. reported a 27
±
32 cm
2
increase in muscle area
in the BFR-RT group compared to placebo after four months of training [
17
]. However,
Hughes et al. found no significant difference between BFR-RT and HL-RT in terms of
quadriceps muscle thickness increase (5.8 ±0.2% vs. 6.7 ±0.3%, p= 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the effects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a significant increase in knee extensor strength in the LL-BFR-RT group at
60
◦
/s (14
±
11% vs. 0
±
6%, p< 0.05) and 120
◦
/s (8
±
5% vs.
−
2
±
5%, p< 0.01), compared
to the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low
risk of bias in random sequence generation, allocation concealment, detection, migration,
and notification. However, this study showed performance bias, and other sources of
bias were also present [
17
]. The study by Hughes et al. had a low risk of bias in random
sequence generation, allocation concealment, and notification. However, this study had
performance and migration biases, and the detection bias remains undetermined [
18
]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notification, but had detection and performance biases [
19
]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [
20
]. Migration and notification biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and allocation
concealment, but performance and detection biases were observed [
21
]. Migration and
notification biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17] Hughes et al. [18] Curran et al. [19] Kacin et al. [20] De Melo et al. [21]
Randomization sequence
generation
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Allocation concealment
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Performance biases
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Detection biases
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy

Diagnostics 2025,15, 382 9 of 13
Table 4. Cont.
Erickson et al. [17] Hughes et al. [18] Curran et al. [19] Kacin et al. [20] De Melo et al. [21]
Migration biases
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Notification biases
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Other sources of bias
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
Low risk of bias:
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
. High risk of bias:
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
. Risk of bias undetermined:
Diagnostics 2025, 15, x FOR PEER REVIEW 9 of 13
area in the BFR-RT group compared to placebo after four months of training [17]. How-
ever, Hughes et al. found no signicant dierence between BFR-RT and HL-RT in terms
of quadriceps muscle thickness increase (5.8 ± 0.2% vs. 6.7 ± 0.3%, p = 0.33) [18].
Three studies (60%) used both strength and endurance criteria to assess the eects of
BFR-RT, including evaluations of isokinetic strength, 1RM, and muscle contraction. Kacin
et al. reported a signicant increase in knee extensor strength in the LL-BFR-RT group at
60°/s (14 ± 11% vs. 0 ± 6%, p < 0.05) and 120°/s (8 ± 5% vs. −2 ± 5%, p < 0.01), compared to
the control group [20].
Data Quality
The risk of bias varied across studies. The study by Erickson et al. showed a low risk
of bias in random sequence generation, allocation concealment, detection, migration, and
notication. However, this study showed performance bias, and other sources of bias
were also present [17]. The study by Hughes et al. had a low risk of bias in random se-
quence generation, allocation concealment, and notication. However, this study had per-
formance and migration biases, and the detection bias remains undetermined [18]. The
study by Curran et al. showed a low risk of bias in random sequence generation, allocation
concealment, and notication, but had detection and performance biases [19]. Migration
bias was undetermined in this study. The study by Kacin et al. had a low risk of bias in
random sequence generation and allocation concealment, but presented performance and
detection biases [20]. Migration and notication biases were undetermined. Finally, the
study by De Melo et al. had a low risk of bias in random sequence generation and alloca-
tion concealment, but performance and detection biases were observed [21]. Migration
and notication biases were undetermined (Table 4).
Table 4. Risk of Cochrane bias in various studies.
Erickson et al. [17]
Hughes et al. [18]
Curran et al. [19]
Kacin et al. [20]
De Melo et al. [21]
Randomization se-
quence generation
Allocation conceal-
ment
Performance biases
Detection biases
Migration biases
Notification biases
Other sources of
bias
Low risk of bias: . High risk of bias: . Risk of bias undetermined: .
4. Discussion
The present systematic review aimed to evaluate the ecacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The ndings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and oers a signi-
cant alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy
.
4. Discussion
The present systematic review aimed to evaluate the efficacy of BFR-RT in improving
quadriceps strength and muscle mass in patients after ACLR. The findings show that BFR-
RT is a promising adjunct to traditional low-load training protocols, and offers a significant
alternative for early- and mid-phase rehabilitation by enabling muscle hypertrophy and
strength gains with reduced joint strain. This review reveals a nuanced view of the efficacy
of BFR-RT in enhancing quadriceps strength and muscle mass after ACLR. Several studies
within this review underscore the potential of BFR-RT for fostering strength gains that
are comparable to, and in some cases greater than, those achieved with traditional HL-
RT. However, the results show variability across studies, which indicates that BFR-RT’s
effectiveness is influenced by specific protocol variables, such as load intensity, cuff pressure,
and timing of the intervention post-surgery.
The current review highlights multiple studies in which BFR-RT led to significant
increases in quadriceps strength. For instance, Hughes et al. demonstrated that BFR-RT
using loads of 30% of the 1RM with occlusion at 80% of the LOP achieved strength gains
comparable to those provided by HL-RT performed at 70% of the 1RM. This finding shows
that BFR-RT can match the effectiveness of higher-load training, a notable advantage in the
early stages post-ACLR, when high mechanical loads are generally contraindicated [
18
].
Furthermore, Kacin et al. reported that BFR-RT resulted in greater gains in isokinetic
strength at both 60
◦
/s and 120
◦
/s compared to a control group without BFR [
20
]. This
improvement in both maximum torque and total work performed emphasizes BFR-RT’s effi-
cacy in building strength across different speeds of muscle contraction, which is particularly
beneficial for functional recovery in ACLR patients.
There are studies in this current review, such as that by Curran et al., that showed
no additional benefit of BFR-RT when combined with high-intensity exercise (e.g., 70%
of 1RM) [
19
]. This indicates that BFR-RT may be most effective when applied in a low-
load context rather than in conjunction with heavy loads, potentially due to the increased
metabolic stress and hypoxic conditions specific to low-load BFR-RT protocols, which
stimulate muscle adaptations without the need for high mechanical loads. The present
review also shows that BFR-RT can be effective for the promotion of muscle hypertrophy
post-ACLR, although the results here are mixed. Erickson et al. observed a notable increase
in quadriceps cross-sectional area in the BFR-RT group, with a 27
±
32 cm
2
difference
compared to a placebo group. This finding aligns with the hypothesis that BFR-RT pro-
motes muscle hypertrophy through mechanisms associated with metabolic stress, such
as increased muscle protein synthesis and satellite cell proliferation, even under low-load
conditions [
17
]. Similarly, Kacin et al. found that low-load BFR-RT significantly increased
quadriceps muscle mass compared to a control group [
20
]. This study’s protocol involved
four sets of knee flexion and extension at 40% of the 1RM with occlusion pressure set at

Diagnostics 2025,15, 382 10 of 13
150 mmHg, underscoring the potential for specific BFR-RT configurations to achieve hyper-
trophy. The significant gains in quadriceps cross-sectional area achieved in this study show
that BFR-RT is particularly effective when combined with moderate occlusion pressures
and moderate training loads, potentially optimizing the balance between metabolic stress
and muscle activation for hypertrophy.
Other studies did not find a statistically significant difference in muscle mass between
BFR-RT and non-BFR-RT groups. For instance, Curran et al. measured rectus femoris mass,
but found no meaningful increase in the BFR-RT group compared to controls, indicating that
the effects of BFR-RT on hypertrophy may vary based on muscle group, training duration,
and protocol parameters [
19
]. Hughes et al. also reported similar muscle thickness increases
in both BFR-RT and HL-RT groups, which indicates that BFR-RT may not universally exceed
the hypertrophic effects of traditional high-load training, but offers a viable alternative in
situations where high loads are unsuitable [18].
In summary, the results of this current review support BFR-RT as a beneficial method
for achieving muscle strength and mass gains in early- and mid-phase rehabilitation after
ACLR. BFR-RT has demonstrated comparable efficacy to HL-RT in strength development,
particularly in protocols involving low to moderate loads. This is significant, given the need
to limit mechanical load on the knee joint in the early stages of recovery. The variability in
hypertrophy outcomes across studies shows that BFR-RT’s effect on muscle mass may be
influenced by factors such as cuff pressure, load intensity, and intervention timing. Further
research with standardized protocols is warranted to optimize BFR-RT application for
consistent hypertrophic outcomes.
4.1. Limitations
A potential limitation of this systematic review is that it was not registered on PROS-
PERO or a similar registry, which could enhance transparency and adherence to predefined
protocols; however, this will be addressed in future research endeavors. The heterogeneity
in study protocols presents a limitation in drawing generalized conclusions regarding
BFR-RT’s efficacy. Variability in factors such as cuff pressure, load intensity (from 30%
to 70% of 1RM), and training duration may influence outcomes and limit comparability
across studies. For example, Erickson et al. included a preoperative BFR-RT protocol,
whereas other studies commenced several weeks post-surgery, likely affecting muscle
recovery pathways and adaptation rates [
17
]. Another limitation is the small sample sizes
across the included studies, which limits statistical power and may bias the results. In
addition, the lack of blinding in most trials presents a risk of performance and detection
bias. Participants and assessors in studies such as those by Hughes et al. were not blinded,
potentially influencing subjective assessments of strength and hypertrophy [
18
]. One of
our limitations is the small number of studies included, because we selected studies from
the last 5 years.
4.2. Clinical Implications and Perspectives
Despite these limitations, the present review supports the clinical potential of BFR-RT
as a low-load alternative in the early rehabilitation of ACLR patients, where traditional
heavy-load training is contraindicated. Its application could potentially improve patient
adherence by reducing the pain associated with high-load exercises, facilitating muscle
recovery (Figure 3). However, to translate BFR-RT into standard clinical practice, further
research is needed to establish standardized protocols that define the optimal cuff pressure,
load intensity, and duration of application for ACLR patients. Future studies with larger,
more homogenous sample populations and robust blinding methodologies are necessary
to confirm BFR-RT’s long-term efficacy and safety. Investigation of the biochemical and

Diagnostics 2025,15, 382 11 of 13
physiological mechanisms underlying BFR-induced hypertrophy, such as BFR’s effects on
protein synthesis and satellite cell activity, would also provide insights into its optimization
of its use in post-operative rehabilitation.
Diagnostics 2025, 15, x FOR PEER REVIEW 11 of 13
variability in hypertrophy outcomes across studies shows that BFR-RT’s eect on muscle
mass may be inuenced by factors such as cu pressure, load intensity, and intervention
timing. Further research with standardized protocols is warranted to optimize BFR-RT
application for consistent hypertrophic outcomes.
4.1. Limitations
A potential limitation of this systematic review is that it was not registered on PROS-
PERO or a similar registry, which could enhance transparency and adherence to prede-
ned protocols; however, this will be addressed in future research endeavors. The heter-
ogeneity in study protocols presents a limitation in drawing generalized conclusions re-
garding BFR-RT’s ecacy. Variability in factors such as cu pressure, load intensity (from
30% to 70% of 1RM), and training duration may inuence outcomes and limit compara-
bility across studies. For example, Erickson et al. included a preoperative BFR-RT proto-
col, whereas other studies commenced several weeks post-surgery, likely aecting muscle
recovery pathways and adaptation rates [17]. Another limitation is the small sample sizes
across the included studies, which limits statistical power and may bias the results. In
addition, the lack of blinding in most trials presents a risk of performance and detection
bias. Participants and assessors in studies such as those by Hughes et al. were not blinded,
potentially inuencing subjective assessments of strength and hypertrophy [18]. One of
our limitations is the small number of studies included, because we selected studies from
the last 5 years.
4.2. Clinical Implications and Perspectives
Despite these limitations, the present review supports the clinical potential of BFR-
RT as a low-load alternative in the early rehabilitation of ACLR patients, where traditional
heavy-load training is contraindicated. Its application could potentially improve patient
adherence by reducing the pain associated with high-load exercises, facilitating muscle
recovery (Figure 3). However, to translate BFR-RT into standard clinical practice, further
research is needed to establish standardized protocols that dene the optimal cu pres-
sure, load intensity, and duration of application for ACLR patients. Future studies with
larger, more homogenous sample populations and robust blinding methodologies are
necessary to conrm BFR-RT’s long-term ecacy and safety. Investigation of the bio-
chemical and physiological mechanisms underlying BFR-induced hypertrophy, such as
BFR’s eects on protein synthesis and satellite cell activity, would also provide insights
into its optimization of its use in post-operative rehabilitation.
Figure 3. A schematic diagram illustrating the possible skeletal muscle and cardiovascular adapta-
tions that are improved with blood ow restriction training compared with work-matched training
[22].
Figure 3. A schematic diagram illustrating the possible skeletal muscle and cardiovascular adap-
tations that are improved with blood flow restriction training compared with work-matched train-
ing [22].
5. Conclusions
BFR-RT shows promise as an effective method for the improvement of quadriceps
strength and muscle mass in the early- and mid-rehabilitation phases after ACLR. BFR-
RT allows strength gains that are comparable to those provided by traditional high-load
resistance training, but with lower intensities, reducing strain on the healing knee joint. This
makes BFR-RT particularly valuable for patients who cannot yet safely undertake heavy-
load exercises post-surgery. This current review indicates that BFR-RT can effectively foster
muscle hypertrophy and strength; however, results vary across studies. This variability
may stem from differences in load intensity, cuff pressure, and protocol timing, which
highlights a need for standardized guidelines to optimize BFR-RT application. Limitations
in current research, such as small sample sizes and a lack of standardized methodologies,
underscore the importance of future studies to confirm these findings and establish best
practices. In conclusion, BFR-RT is a promising addition to ACLR rehabilitation, which
offers a safe and effective way to mitigate muscle weakness. Further research is essential
to validate its benefits and refine protocols, in order to ensure its integration into clinical
practice for optimal patient outcomes.
Author Contributions: Conceptualization, A.M.--S. and M.B.; methodology, A.M.--S., F.F., G.K.
and T.E.H.; validation, J.M., F.F. and T.E.H.; formal analysis, A.M.--S.; resources, J.M., T.E.H. and
G.K.; writing—original draft preparation, A.M.--S.; writing—review and editing, J.M., M.D. and
F.F.; supervision, F.F.; project administration, F.F. All authors have read and agreed to the published
version of the manuscript.
Funding: This research received no external funding.
Conflicts of Interest: The authors declare no conflicts of interest.

Diagnostics 2025,15, 382 12 of 13
References
1.
Joseph, A.M.; Collins, C.L.; Henke, N.M.; Yard, E.E.; Fields, S.K.; Comstock, R.D. A Multisport Epidemiologic Comparison of
Anterior Cruciate Ligament Injuries in High School Athletics. J. Athl. Train. 2013,48, 810. [CrossRef] [PubMed]
2.
Vincelot-Chainard, C.; Buisson, X.; Taburet, J.-F.; Djian, P.; Robert, H. ACL autograft reconstruction revisions with tendon
allografts: Possibilities and outcomes. A one-year follow-up of 39 patients. Orthop. Traumatol. Surg. Res. 2022,108, 102832.
[CrossRef] [PubMed]
3.
Evans, J.; Mabrouk, A.; Nielson, J.L. Anterior Cruciate Ligament Knee Injury. In StatPearls; StatPearls Publishing: Treasure Island,
FL, USA, 2024.
4.
Lefevre, N.; Klouche, S.; Herman, S.; Bohu, Y. Les facteurs de risques de rupture du ligament croisé antérieur: Le genre féminin.
J. Traumatol. Sport. 2014,31, 58–62. [CrossRef]
5.
Filbay, S.R.; Grindem, H. Evidence-based recommendations for the management of anterior cruciate ligament (ACL) rupture.
Best. Pract. Res. Clin. Rheumatol. 2019,33, 33–47. [CrossRef]
6.
Kotsifaki, R.; Korakakis, V.; King, E.; Barbosa, O.; Maree, D.; Pantouveris, M.; Whiteley, R. Aspetar clinical practice guideline on
rehabilitation after anterior cruciate ligament reconstruction. Br. J. Sports Med. 2023,57, 500–514. [CrossRef]
7.
Palmieri-Smith, R.M.; Lepley, L.K. Quadriceps Strength Asymmetry After Anterior Cruciate Ligament Reconstruction Alters
Knee Joint Biomechanics and Functional Performance at Time of Return to Activity. Am. J. Sports Med. 2015,43, 1662–1669.
[CrossRef]
8.
Hart, J.M.; Pietrosimone, B.; Hertel, J.; Ingersoll, C.D. Quadriceps activation following knee injuries: A systematic review. J. Athl.
Train. 2010,45, 87–97. [CrossRef]
9.
Lepley, L.K. Deficits in Quadriceps Strength and Patient-Oriented Outcomes at Return to Activity After ACL Reconstruction: A
Review of the Current Literature. Sports Health 2015,7, 231–238. [CrossRef]
10.
Hughes, L.; Paton, B.; Rosenblatt, B.; Gissane, C.; Patterson, S.D. Blood flow restriction training in clinical musculoskeletal
rehabilitation: A systematic review and meta-analysis. Br. J. Sports Med. 2017,51, 1003–1011. [CrossRef]
11.
Patterson, S.D.; Hughes, L.; Warmington, S.; Burr, J.; Scott, B.R.; Owens, J.; Loenneke, J. Blood Flow Restriction Exercise:
Considerations of Methodology, Application, and Safety. Front. Physiol. 2019,10, 533. [CrossRef]
12.
Caetano, D.; Oliveira, C.; Correia, C.; Barbosa, P.; Montes, A.; Carvalho, P. Rehabilitation outcomes and parameters of blood flow
restriction training in ACL injury: A scoping review. Phys. Ther. Sport 2021,49, 129–137. [CrossRef] [PubMed]
13.
Herbawi, F.; Lozano-Lozano, M.; Lopez-Garzon, M.; Postigo-Martin, P.; Ortiz-Comino, L.; Martin-Alguacil, J.L.; Fernandez-Lao, C.
A Systematic Review and Meta-Analysis of Strength Recovery Measured by Isokinetic Dynamometer Technology after Anterior
Cruciate Ligament Reconstruction Using Quadriceps Tendon Autografts vs. Hamstring Tendon Autografts or Patellar Tendon
Autografts. Int. J. Environ. Res. Public Health 2022,19, 6764. [CrossRef] [PubMed]
14.
Fujita, S.; Abe, T.; Drummond, M.J.; Cadenas, J.G.; Dreyer, H.C.; Sato, Y.; Rasmussen, B.B. Blood flow restriction during low-
intensity resistance exercise increases S6K1 phosphorylation and muscle protein synthesis. J. Appl. Physiol. Bethesda Md. 2007,103,
903–910. [CrossRef] [PubMed]
15.
Dolin, R.; Ben Zaki, B. L’entraînement sous restriction du flux sanguin, ou «Blood Flow Restriction», une alternative au renforcement
musculaire àcharge élevée. Kinésithérapie Rev. 2022,22, 34–40. [CrossRef]
16.
Page, M.J.; McKenzie, J.E.; Bossuyt, P.M.; Boutron, I.; Hoffmann, T.C.; Mulrow, C.D.; Moher, D. The PRISMA 2020 statement: An
updated guideline for reporting systematic reviews. BMJ 2021,372, n71. [CrossRef]
17.
Erickson, L.N.; Lucas, K.C.H.; Davis, K.A.; Jacobs, C.A.; Thompson, K.L.; Hardy, P.A.; Andersen, A.H.; Fry, C.S.; Noehren, B.W.
Effect of Blood Flow Restriction Training on Quadriceps Muscle Strength, Morphology, Physiology, and Knee Biomechanics
Before and After Anterior Cruciate Ligament Reconstruction: Protocol for a Randomized Clinical Trial. Phys. Ther. 2019,99,
1010–1019. [CrossRef]
18.
Hughes, L.; Rosenblatt, B.; Haddad, F.; Gissane, C.; McCarthy, D.; Clarke, T.; Ferris, G.; Dawes, J.; Paton, B.; Patterson, S.D.
Comparing the Effectiveness of Blood Flow Restriction and Traditional Heavy Load Resistance Training in the Post-Surgery
Rehabilitation of Anterior Cruciate Ligament Reconstruction Patients: A UK National Health Service Randomised Controlled
Trial. Sports Med. 2019,49, 1787–1805. [CrossRef]
19.
Curran, M.T.; Bedi, A.; Mendias, C.L.; Wojtys, E.M.; Kujawa, M.V.; Palmieri-Smith, R.M. Blood Flow Restriction Training Applied
with High-Intensity Exercise Does Not Improve Quadriceps Muscle Function After Anterior Cruciate Ligament Reconstruction:
A Randomized Controlled Trial. Am. J. Sports Med. 2020,48, 825–837. [CrossRef]
20.
Kacin, A.; Drobniˇc, M.; Marš, T.; Miš, K.; Petriˇc, M.; Weber, D.; Tomc Žargi, T.; Martinˇciˇc, D.; Pirkmajer, S. Functional and
molecular adaptations of quadriceps and hamstring muscles to blood flow restricted training in patients with ACL rupture. Scand.
J. Med. Sci. Sports 2021,31, 1636–1646. [CrossRef]

Diagnostics 2025,15, 382 13 of 13
21.
Vieira de Melo, R.F.; Komatsu, W.R.; Freitas, M.S.; de Vieira de Melo, M.E.; Cohen, M. Comparison of Quadriceps and Hamstring
Muscle Strength after Exercises with and without Blood Flow Restriction following Anterior Cruciate Ligament Surgery: A
Randomized Controlled Trial. J. Rehabil. Med. 2022,54, jrm00337. [CrossRef]
22.
Pignanelli, C.; Christiansen, D.; Burr, J.F. Blood flow restriction training and the high-performance athlete: Science to application.
J. Appl. Physiol. Bethesda Md. 2021,130, 1163–1170. [CrossRef]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual
author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to
people or property resulting from any ideas, methods, instructions or products referred to in the content.